Field of the Invention
The present invention relates to a process to separate levulinic acid from a biomass hydrolysate using as an organic solvent a substituted benzene and to the use of such substituted benzenes in the separation of levulinic acid from a biomass hydrolysate.
Background of the Invention
Isolation of many industrial compounds involves the use of both extraction and distillation. Extraction takes advantage of differences in the chemical properties of the feed components, such as differences in polarity and hydrophobic/hydrophilic character to separate them (T. C. Frank, L. Dahuron, B. S. Holden, W. D. Prince, A. F. Seibert, L. C. Wilson, Liquid-liquid extraction and other liquid-liquid operations and equipment in Perry's Chemical Engineering Handbook, 8th Edition, Section 15). After a compound of interest has been extracted from an aqueous composition the valuable compound is usually further purified by subjecting the organic phase to distillation. A suitable extraction solvent must not only give good extraction efficiency, but must also be compatible with a distillation as a subsequent separation step. For example, a solvent must not form a complex with the target compound during distillation, or result in the formation of degradation or side products. In other words, a solvent which gives good extraction efficiency but results in the formation of side products in a distillation is not suitable. Likewise, a solvent which gives no problems during distillation but gives poor extraction efficiency is also not suitable.